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Signal transfer method and equipment for electric machine equipped with three-phase power supply cable

US 4,862,157 A · Assignee: Charbonnages De France · Inventors: Noel; Marc

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Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Filed January 20, 1988 and granted August 29, 1989. A patent filed before June 8, 1995 lasts 17 years from grant or 20 from filing, whichever is longer, so its term ended January 20, 2008.
  • Any extension is capped at five years, so it can't still be in force.
  • We haven't checked its US family, and a later related patent could still be in force. We check US rights only.
FiledJanuary 20, 1988
GrantedAugust 29, 1989
Term endedJanuary 20, 2008
Application number07/147101
Classification (CPC)E21C35/24 +2 more
Length15 pages

Timeline

Timeline From USPTO dates

1989199119931995199719992001200320052007Application filedJan 20, 1988Patent grantedAug 29, 1989Term endedJan 20, 2008

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